Early signs of genetic or chromosomal syndromes at 18–24 months

When a little one reaches their second birthday a touch differently, a gentle, knowing look can open doors to the right support early.

In short

Between 18 and 24 months, possible early signs that a genetic or chromosomal syndrome may be affecting development include a noticeable lag across several areas at once — late walking, few or no words, low muscle tone (a 'floppy' feel), feeding or growth difficulties, and sometimes distinctive facial or physical features. Many syndromes are suspected from birth or infancy, but some become clearer in toddlerhood as developmental gaps emerge. These are signs to observe and discuss with a paediatrician, not to label at home, and a developmental and genetic review is the sensible next step.

Early signs to watch (18–24 months)

Development across several areas

• A delay in more than one domain together — for example walking and talking and using hands — rather than just one
• Very few words, or not yet starting to combine words, alongside slow understanding
• Not yet walking, or walking with a wide, unsteady gait
• Difficulty with fine movements like picking up small objects or self-feeding

Body and growth

• Low muscle tone (a soft, floppy feel) or, less often, unusual stiffness
• Slow growth, very small or large head size, or being notably small or large for age
• Ongoing feeding difficulties, reflux, or constipation
• Recurrent infections, or known heart, hearing or vision concerns

Appearance and other clues

• Distinctive facial features, unusual hand or foot creases, or differences a doctor notes
• A family history of a known genetic condition, or earlier 'soft' concerns at newborn or infant checks

What shifts this from ordinary variation towards a review is a pattern across multiple areas, physical or growth differences alongside developmental delay, or a clinician's earlier note — warmth, eye contact and connection can remain lovely throughout, and that is reassuring.

When to seek a check

Many toddlers develop at their own pace, and one isolated delay is rarely cause for alarm. But when delays span several areas, when there are physical or growth differences, or when a paediatrician has previously flagged something, a developmental review and a paediatric genetics referral are wise. Diagnosis often involves blood tests (such as a chromosomal microarray) arranged by a doctor — and importantly, support for development can begin straight away, well before any test result is in. Early, strengths-first therapy helps every child build on what they can do.

The Pinnacle way

At Pinnacle Blooms Network, we begin with your child's strengths and the everyday things that help them thrive, then build a plan around them — often working hand-in-hand with your paediatrician and genetics team. Play-based early intervention therapy supports movement, communication and daily skills, with parents coached as partners. A clinical AbilityScore® and any diagnosis are formed only at a Pinnacle Blooms Network centre under qualified clinician care; nothing here is a diagnosis. You can learn more about genetic and chromosomal syndromes and how support works. Across 70+ centres in 4 states and 4.95 lakh+ families served, our aim is steady, confident progress.

Trusted sources

Aligned with WHO ICD-11 guidance on developmental conditions, American Academy of Pediatrics and HealthyChildren.org guidance on developmental surveillance and milestones, and CDC resources on developmental monitoring in toddlers.

Next step — if this sounds like your little one, book a developmental screen with our clinical team on WhatsApp at +91 91001 81181, and let's understand your child together.

This is general information, not a diagnosis — individual assessment and diagnosis require an appropriately qualified healthcare professional.